>Wind resistance and speed really seem to be the base factors on highway fuel
>economy. Engine choices and gearing have some effect and then there is the
>Diesel option.  My current Diesel motor home really gets the same mileage as
>my last gas one. Yes it weighs more and is longer, but it seems the wind
>resistance is the major factor.

  110kmh (~70mph) seems to be the stone wall... above this and
fuel-consumption jumps, whatever the vehicle.

My 89 diesel Corolla commercial wagon got the same consumption with a
low-ratio commercial diff as it does now with a sedan diff. We'll see
what it does with the 2.0 turbodiesel from a 94 Camry now
installed... and whether the head cracks!
--
Andrew Grebneff
Dunedin
New Zealand
Fossil preparator
<andrew.grebneff@stonebow.otago.ac.nz>
Seashell, Macintosh, VW/Toyota van nut